Search Results (66)

Angling tourism is becoming increasingly important at Central Europe’s largest lowland reservoir, Lake Tisza. The lake, created in the 1970s, covers 127 km² and has been increasingly used for recreational and nature conservation purposes recently. This study seeks to identify anglers’ site selection preferences at Lake Tisza, considering hydrological and ecological aspects, in support of sustainable site management. In order to achieve this, an in-person questionnaire survey was carried out covering the whole area during springtime 2024. During the survey period, a total of 224 anglers provided answers about their preferred location and recreational characteristics. Data processing was carried out using SPSS 26 and ESRI ArcGIS version 10.4.1. Based on the created catchment area map, it was found that a significant proportion (74%) of anglers arrive from within a 50 km radius, but the lake also has appeal outside the country. A total of 53.1% of respondents visit the lake several times per month, typically for fishing purposes. In addition, cycling, walking and picnicking are popular recreational activities among anglers. The respondents considering different landscapes (pictures showed by the interviewers) for angling prefer shaded areas with vegetation and a narrow view of the wide expanse of water (62%). The results of the open-ended questions indicate that site selection is primarily based on the existence of a shadow (49.5%), and suitability for fishing is only the second aspect (40.6%). Our study also highlighted the international trend that anglers are more interested in leisure activities in a green environment. In addition, the results have practical significance for more successful recreation planning and sustainable site management. Full article

The management of reservoir dams in the context of observed climate changes and changing environmental conditions is becoming an increasingly significant challenge. Changes in the regimes of rivers feeding the reservoirs, sudden floods, long periods of drought, shallowing of reservoirs, water pollution, and algal blooms create unprecedented threats to the operation of these reservoirs. Among these challenges, the most crucial seems to be the proper management of available water resources, which condition the existence of the reservoir. The location of the reservoir has a significant impact on how water management is conducted. In the case of mountain and upland reservoirs created for flood protection of areas downstream, water management practices differ significantly from those for lowland reservoirs, which primarily serve to retain water for industrial and agricultural needs in the area, with an additional flood protection function. The aim of this study was to assess the factors determining the supply of lowland reservoirs using the example of the Pakoski Reservoir (Central–Western Poland) and to propose actions that would allow more efficient management of water resources in the catchment and reservoir, enabling the preservation of the current morphometric parameters in the face of climate change, adverse environmental phenomena, and increased anthropogenic pressure in the catchment area. This study focused on the Pakoski Reservoir, located in the southern part of the Kuyavian–Pomeranian Voivodeship. It was constructed fifty years ago as a result of damming water in the river systems of the Noteć and Mała Noteć Rivers. For decades, it served its functions, and its management posed no major issues. However, over the past decade, due to environmental changes and human activities in the catchment area, the reservoir has increasingly faced problems with filling. Full article

Climate change causes a problem for the energy system in Poland, which is based on the availability of water resources throughout the year. In situations of water scarcity resulting from increased demand or due to water deficits caused by the phenomenon of drought, it is necessary to develop efficient management methods that take into account the needs of all stakeholders and obtaining approval for new investments. The principles of Integrated Water Resources Management (IWRM) enable this efficiency to be achieved. The research used 51 questions in 3 surveys to assess the potential for IWRM implementation in 3 catchments located in an area of southern and south-western Poland with different topography, regional and socio-economic characteristics, i.e., the Białka (tourism domination), the Nysa Kłodzka (potential for hydropower) and the Widawa (lowland character). In order to interpret the results, the author’s method of grouping survey questions from different sources was applied. The results of the study showed that there is considerable social potential and willingness to develop cooperation between different stakeholder groups but there are barriers related to the state of knowledge and its transfer between stakeholders. It is important not to ignore the stakeholders whose resistance can effectively delay investment processes. Full article

The objectives of our study were to analyse the degree of human pressure within the lowland river catchment in relation to the mollusc communities and to assess the usefulness of the River Habitat Survey as a field method in determining the human pressure in the mollusc biodiversity context. The River Habitat Survey (RHS), an essential method for hydromorphological studies of rivers under the requirements of the European Union Water Framework Directive, was applied. This study showed that the diversity of molluscs was impacted by several environmental factors acting simultaneously, including pH, concentration of ammonium nitrogen in water, and the habitat features depending on the degree of human pressure on the river. The result of the RHS method confirmed that the occurrence of molluscs including Unio crassus and Pseudanodonta complanata, the endangered species on a global scale, was associated with the extensive presence of several natural habitat features in the river channel. The RHS method proved to be an indispensable tool for assessing the relationships between the diversity of aquatic organisms and the degree of habitat anthropogenic modification of river environments. It seems innovative and necessary, especially in restoring the natural character of rivers. Full article

This article addresses the issue of droughts in recent years in Poland and their impact on the state of groundwater resources. This paper presents the challenges arising from the increasing demand for the use of groundwater for irrigation in agriculture, supplementing water shortages, and potential threats to the water supply of rural waterworks. The main part of this paper focuses on a small catchment area in the Mazovian Lowland, which is one of the driest regions in the country. This article includes definitions, characteristics, and causes of hydrologic and hydrogeologic droughts during the period 2011–2020. In the discussed area, there is generally one groundwater level of the Quaternary age, primarily recharged by rainfall infiltration, which is utilized by all dug wells and a number of drilled wells. The source material consisted of daily measurements of groundwater levels with a free surface from three piezometers located in different land use areas (forest, agricultural, and sparse development). Additionally, daily flows of the Zagożdżonka River at the Płachty Stare gauge station were examined, where the drying of the riverbed in the upper reaches has been observed in recent years. This study investigated the dynamics of hydrogeologic droughts in renewable groundwater resources and the rate of their decline in relation to hydrologic droughts of surface waters. Full article

Agricultural practices have a significant impact on stream water quality in rural landscapes; however, there is still little empirical evidence of how different types of cultivation alter the hydrochemistry of running water. Thus, the current study explored the spatial dynamics of selected ion concentrations and their land cover dependence in lowland agricultural catchments. From November 2021 to October 2022, water samples were collected from 30 sites located across small tributaries of the rivers Bzura, Pilica, and Radomka for chemical analysis of their NO₃, NO₂, NH₄, Ca, Mg, K, Na, As, Ba, Sr, and V concentrations. The results indicated a clear spatial heterogeneity of water quality, related to lithology and dominant land cover evaluated with the CORINE Land Cover 2018 dataset. Overall, sites representing agricultural land promoted increased concentrations of major and trace elements, while those with pepper cultivation were additionally contaminated with NO₃ and NO₂. The correlation performance for nitrogen compounds was the highest for narrower buffer zones, which was not documented for major and trace elements, which were linked more strongly with land cover at larger scales. Such new insights into the water quality dynamics of lowland agricultural catchments, being a simultaneous reflection of lithology, agricultural practices, and several municipal impacts, have significant implications for appropriate water management in rural landscapes. Full article

The hydrological assessment of the Vistula River basin in the near future will be a key element in the development of strategies to adapt agriculture to climate change. The Vistula River basin covers 61% of Poland’s area (190,062 km²) and is mainly used for agricultural production. The aim of this study is to assess the water balance of the Vistula River basin from the perspective of 2050 based on the analysis of two climate scenarios, RCP 4.5 and RCP 8.5, and the three climate models ICHEC-EC-EARTH_KNMI-RACMO22E (A), ICHEC-EC-EARTH_DMI-HIRHAM5 (B), and ICHEC-EC-EARTH_SMHI-RCA4 (C). This paper presents the steps in the development of the SWAT model and the results of the hydrological analysis of the Vistula catchment. Calibration and validation of the model were carried out using the SUFI-2 algorithm in the SWAT-CUP programme for 2013–2018. The data used to calibrate the SWAT model are monthly flow measurements [m³/s] from the measurement station in Tczew, located near the estuary of the Vistula basin to the Baltic Sea. The summary result of the work is the results of modelling the flow of the Vistula River catchment for different climate scenarios in the 2020–2050 perspective. The average annual precipitation for all projections in 2021–2030, 2031–2040, and 2041–2050 will be higher by up to 22% (763 mm) (RCP 8.5.C for 2041–2050) compared to the 2013–2018 simulation years (624 mm). The average annual temperature for most climate projections for 2021–2030 will fall to as low as 8.7 °C (RCP 4.5.B) compared to the 2013–2018 simulation period (9.2 °C). In contrast, for all projections in 2031–2040 and 2041–2050, the average annual temperature will increase to as much as 10.3 °C (RCP 8.5.C). The simulation results for the climate projections (2020–2050) indicate that there are no clear trends of change in the water management of the Vistula River basin for the coming decades. According to scenarios RCP 4.5.A, RCP 8.5.A, and RCP 8.5.B, the annual sums of potential evapotranspiration show a slight downward trend. On the other hand, for the RCP 8.5.C and RCP 4.5.C projections and the climate change scenario RCP 4.5.B, the results obtained show a slight upward trend in the annual sum of potential evapotranspiration. For the overall evapotranspiration and potential evapotranspiration assessment for all climate projections analysed, the annual evapotranspiration total shows a clear increase compared to the 2013–2018 baseline period. The average annual actual evapotranspiration for all projections in 2021–2030, 2031–2040, and 2041–2050 will increase up to 467 mm (RCP 4.5.A—2021–2030) compared to the 2013–2018 simulation period of 401 mm. The average annual potential evapotranspiration for all projections in 2021–2030, 2031–2040, and 2041–2050 will increase up to 755 mm (RCP 8.5.C—2031–2040) compared to the 2013–2018 simulation period—616 mm. The analysis of the total runoff in all climate models for the RCP 4.5 scenario shows that the annual average total runoff tends to decrease. The results of the simulations carried out for the RCP 8.5 scenario, which are generally characterised by an increase in total runoff in subsequent years, are different. When analysing annual total runoff on a regional basis, it appears that for most of the climate projections analysed (except for the RCP 8.5.A scenario), annual runoff will be lower, especially in the lowlands in the central part of the Vistula basin. In regions where the increase in precipitation is greatest in the north-western and southern basins, higher total runoff should be expected. The analysis of the total runoff in all climate models for the RCP 4.5 scenario shows that the annual average total runoff tends to decrease. The results of the simulations carried out for the RCP 8.5 scenario, which are generally characterised by an increase in total runoff in subsequent years, are different. When analysing annual total runoff on a regional basis, it appears that for most of the climate projections analysed (except for the RCP 8.5.A scenario), annual runoff will be lower, especially in the lowlands in the central part of the Vistula basin. In regions where the increase in precipitation is greatest in the north-western and southern basins, higher total runoff should be expected. Full article

The hydrotechnical construction, damming up the riverbed, creates two zones of hydraulic conditions, which affect the water discharge and sediment transport routes, as well as plant species composition, as a habitat answer to the hydraulic regime. This study examined the diversity of the vascular and rush plant species upstream and downstream of the weir. The Świder River, a small lowland river in Central Poland, was chosen as a study area. An examined river reach was located at 21 + 340 kilometers of the Świder River. Vegetation properties, plant species, and granulometric fraction composition were recognized at chosen cross-sections along the riverbed where specific hydraulic conditions could be met. The spatial distribution of vortices, smooth or rapid flow areas, and velocity pulsations influence the biotic environment, thereby affecting the species composition, quantity, and plant diversity. In the headwater zone, an environment more favorable to grain accumulation could be met, which was mixed with organic components in an agricultural catchment area. This phenomenon leads to creating favorable conditions for increased biodiversity. The present study demonstrated that small weirs could positively affect the composition of vascular and rush plants. Full article

Climate change and water scarcity increase the vulnerability of crop production and other ecosystem services (ES) in flood-protected lowlands under a continental climate. Restoration of wetlands leads to a higher water-buffering capacity of the landscape, strengthening various ecosystem services, and fostering adaptation to climatic, ecological, and agricultural challenges. Such restoration efforts require extensive land-use change, leading to trade-offs in provisioning and regulating ES. However, knowledge is limited about these situations, especially in the case of lowland areas. Here, we introduce a hydrological analysis in a 243 km² flood-protected catchment in the Great Hungarian Plain, mapping the potential hydrological effects of water-retention scenarios on groundwater levels. We point out how the simulated groundwater levels will be used for estimating the changes in crop yields and tree growth (provisioning services). The introduced hydrological analysis and preliminary results for crop-yield estimates suggest a significant and scalable capacity for a nature-based hydrological adaptation: the extent of inundated areas could be increased stepwise and water retention could locally compensate dry periods due to the buffering effect of inundated meanders. Full article

Urban roads in China, particularly low-lying areas such as underpasses, tunnels, and culverts, are highly vulnerable to the dangers of urban pluvial flooding. We used spatial interpolation methods and limited measured data to assign elevation values to the road surface. The road network was divided into tiny squares, enabling us to calculate each square’s elevation, slope, and curvature. Statistical analysis was then employed to evaluate the impact of terrain on flood characteristics in urban road systems. Our analysis reveals a strong spatial correspondence between the distribution of flood-prone points and the curvature parameters of the terrain. The spatial coincidence rate can reach 100% when an appropriate sampling scale is chosen. The presence of depressions is necessary but insufficient for forming flood-prone points. In lowland/gentle slope (LL/GS) areas with higher drainage pressure, we observe a significant negative correlation between flood-prone points and terrain curvature (Spearman’s r = 0.205, p < 0.01). However, in highland/steep slope (HL/SS) areas, we find no significant correlation between them. Notably, terrain matters, but effective drainage is more influential in flood-prone areas. The maximum flood depth (MFD), submerged area, and ponding volume during urban pluvial flooding are constrained by depression topography, while the characteristics of the upstream catchment area also play a role in determining the MFD and flood peak lag time(FPLT). Larger upstream catchment areas and longer flow paths normally result in greater MFD and longer emergency response times/FPLT. Additionally, a higher flow path gradient will directly contribute to an increased flood risk (greater MFD and shorter FPLT). These findings have important implications for flood risk identification and the development of effective flood mitigation strategies. Full article

The objectives of our survey were to determine the most important environmental factors within buffer zones that influenced mollusc communities and to evaluate the ecological conservation value of natural aquatic habitats (NAHs) that support mollusc species. Analysis of the spatial structure of buffer zones and catchments was based on a set of landscape metrics. Land cover classes were determined, and buffer zones within a radius of 500 m from a sampling point were marked out. Mollusc samples were collected from each NAHs. Our results showed that the number of patches and mean patch size were most associated with the distribution of mollusc species. Within patches of buffer zones, the length of the catchment boundaries with low-density housing, an increasing area of forest and pH of the water were also significant. Our results proved that landscape metrics provide essential information about catchment anthropogenic transformation. Therefore, landscape metrics and the designated buffer zones should be included in restoration plans for the river, water bodies and adjacent habitats as elements of modern, sustainable water management. NAHs located along a valley of a lowland river provide refuges for molluscs, play an essential role in the dispersal of IAS, create important protective biogeochemical barriers for rivers, constitute necessary sources of moisture and water and support microhabitats for distinct mollusc communities, especially in the context of global warming. Full article

Metals stored in sediments of lakes can bioaccumulate through the food chain, posing a risk to the environment and human health. Alpine lakes are supposed to be less affected by pollution than lowland lakes and are vulnerable to any changes and impacts in their catchment areas because of their remote position and ultra-oligotrophic character. Therefore, we used a model Alpine lake, Bohinj (in the Triglav National Park, Julian Alps, Slovenia), to evaluate the load of metals in the abiotic and biotic compartments of the ecosystem, in order to assess the spatial distribution of metals, and finally, to determine whether past and present human activities in the lake’s catchment area may be causing pollution. To this aim, the contents of Cu, Pb, Cr, Cd, Co, Mn, Fe, Zn, Hg and Ni in the sediment, water, and macrophyte samples were determined. The results showed that the average content of some toxic elements, especially in the sediments (Cd 0.52 mg/kg; Hg 0.03 mg/kg) and plants (Co 0.71 mg/kg; Cr 5.88 mg/kg) was elevated compared to natural background values. High Hg contents could be connected with natural geological sources, while other elements were probably of anthropogenic origin. High levels of all elements in the eastern part of the lake indicated long-term pollution, which could be a consequence of past iron extraction and military activities in the vicinity. On the other hand, high contents of elements in the water suggests that intensive touristic activities in the area may cause temporal pollution in the summer. The study sheds light on complicated processes governing the distribution of trace metals in Alpine lakes. Full article

Riverbed sediments in agricultural landscapes are loaded with phosphorus (P). They may act as a source or sink for riverine P, possibly causing harmful algae blooms and eutrophication in streams and receiving water bodies, including coastal waters. In this study, we aimed at identifying the labile, moderately labile, and stable P fraction (Hedley fractionation) in sediments of a northeastern German river basin (3000 km²). A non-metrical multidimensional scaling (NMDS) was used to identify the most significant environmental predictors of the P fractionation in sediments. The total P contents of the sediments varied over a wide range (698 ± 701 mg P kg⁻¹ sediment⁻¹), spanning from 98 to 2648 mg P kg⁻¹ sediment⁻¹. Adjacent agricultural reference soils had markedly lower total P contents of 354 ± 132 mg P kg⁻¹ soil⁻¹, ranging from 146 to 483 P kg⁻¹ soil⁻¹. There were almost no differences between the P contents of the top (0–2 cm) and the bottom (2–10 cm) layer. The dominant P fractions were the moderately labile (NaOH-P) and the stable (H₂SO₄-P) fractions, which accounted for more than 50% of the total P at each sampling point. The NMDS revealed that iron and aluminum contents, as well as land use, are significant predictors for the P fractionation of the sediment. The sediment P-composition reflects the P-status of the agriculturally used mineral soils. However, the size of the contributing catchment as well as the length of the water way have no effects on sediment P. In conclusion, sediment P stocks, though variable, may impede the good ecological status of river waters for decades, especially in lowland basins where hydraulic conditions and a very low stream velocity often create low redox and P dissolution conditions in sediments. Full article

Machine learning (ML) algorithms slowly establish acceptance for the purpose of streamflow modelling within the hydrological community. Yet, generally valid statements about the modelling behavior of the ML models remain vague due to the uniqueness of catchment areas. We compared two ML models, RNN and LSTM, to the conceptual hydrological model Hydrologiska Byråns Vattenbalansavdelning (HBV) within the low-land Ems catchment in Germany. Furthermore, we implemented a simple routing routine in the ML models and used simulated upstream streamflow as forcing data to test whether the individual model errors accumulate. The ML models have a superior model performance compared to the HBV model for a wide range of statistical performance indices. Yet, the ML models show a performance decline for low-flows in two of the sub-catchments. Signature indices sampling the flow duration curve reveal that the ML models in our study provide a good representation of the water balance, whereas the HBV model instead has its strength in the reproduction of streamflow dynamics. Regarding the applied routing routine in the ML models, there are no strong indications of an increasing error rising upstream to downstream throughout the sub-catchments. Full article

River-flow forecasts are important for the management and planning of water resources and their rational use. The present study, based on direct multistep-ahead forecasting with multiple time series specific to the XGBoost algorithm, estimates the long-term changes and forecast monthly flows of selected rivers in Ukraine. In a new, applied approach, a single multioutput model was proposed that forecasts over both short- and long-term horizons using grouped or hierarchical data series. Three forecast stages were considered: using train and test subsets, using a model with train-test data, and training with all data. The historical period included the measurements of the monthly flows, precipitation, and air temperature in the period 1961–2020. The forecast horizons of 12, 60, and 120 months into the future were selected for this dataset, i.e., December 2021, December 2025, and December 2030. The research was conducted for diverse hydrological systems: the Prut, a mountain river; the Styr, an upland river; and the Sula, a lowland river in relation to the variability and forecasts of precipitation and air temperature. The results of the analyses showed a varying degree of sensitivity among rivers to changes in precipitation and air temperature and different projections for future time horizons of 12, 60, and 120 months. For all studied rivers, variable dynamics of flow was observed in the years 1961–2020, yet with a clearly marked decrease in monthly flows during in the final, 2010–2020 decade. The last decade of low flows on the Prut and Styr rivers was preceded by their noticeable increase in the earlier decade (2000–2010). In the case of the Sula River, a continuous decrease in monthly flows has been observed since the end of the 1990s, with a global minimum in the decade 2010–2020. Two patterns were obtained in the forecasts: a decrease in flow for the rivers Prut (6%) and the Styr (12–14%), accompanied by a decrease in precipitation and an increase in air temperature until 2030, and for the Sula River, an increase in flow (16–23%), with a slight increase in precipitation and an increase in air temperature. The predicted changes in the flows of the Prut, the Styr, and the Sula rivers correspond to forecasts in other regions of Ukraine and Europe. The performance of the models over a variety of available datasets over time was assessed and hyperparameters, which minimize the forecast error over the relevant forecast horizons, were selected. The obtained RMSE parameter values indicate high variability in hydrological and meteorological data in the catchment areas and not very good fit of retrospective data regardless of the selected horizon length. The advantages of this model, which was used in the work for forecasting monthly river flows in Ukraine, include modelling multiple time series simultaneously with a single model, the simplicity of the modelling, potentially more-robust results because of pooling data across time series, and solving the “cold start” problem when few data points were available for a given time series. The model, because of its universality, can be used in forecasting hydrological and meteorological parameters in other catchments, irrespective of their geographic location. Full article